Thyroid Function and Disorders During Pregnancy: Evaluating Statements

This section evaluates each statement regarding thyroid function and disorders in pregnancy to identify the one that is NOT true.

Statement Analysis

• Statement 1: Placental Metabolism of Thyroxine

  This statement is true. The placenta increases the metabolism of thyroxine (T4) during pregnancy. Hormones like human chorionic gonadotropin (hCG) produced by the placenta can stimulate the maternal thyroid gland, increasing thyroid hormone production and turnover.

• Statement 2: Hyperemesis Gravidarum and Thyrotoxicosis

  This statement is true. Hyperemesis gravidarum, characterized by severe nausea and vomiting, is often linked to elevated hCG levels. High hCG levels can mimic thyroid-stimulating hormone (TSH), potentially leading to transient thyrotoxicosis symptoms.

• Statement 3: Levothyroxine Dose Adjustment in Early Pregnancy

  This statement is NOT true. During early pregnancy, the body's requirement for thyroid hormone generally increases due to factors like increased thyroid hormone-binding globulin (TBG) levels and fetal demand. Consequently, the dose of levothyroxine replacement therapy typically needs to be increased by approximately 30-50%, not decreased.

• Statement 4: Subclinical Hypothyroidism and Offspring Cognition

  This statement is true. Maternal hypothyroidism during pregnancy, even subclinical forms, is associated with potential risks to fetal neurodevelopment. Impaired cognitive development in the offspring has been observed in infants born to mothers with untreated or undertreated hypothyroidism.

Conclusion

Based on the analysis, the statement that levothyroxine replacement therapy dose should be decreased by 30–50% early in pregnancy is incorrect. The dose usually requires an increase.